Attachment for grinding screw-threaded articles



J. M. STRYHAL. ATTACHMENT FOR GRINDING SCREW THREADED ARTICLES. APPLICATION FILED JUNE 23, 1917.

1,355,710. Patented 0% 12,1920.

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J. M. STRYHAL. FOR GRINDING SCREW THREADED ARTICLES.

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ATTORNEY.

J. M. 'STRYHAL. ATTACHMENT FOR GRINDING SCREW THREADED ARTICLES.

APPLICATION FILED JUNE 23, 1911.

1,355,710. Patented Oct. 1 ,1920.

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J. M. STRYHAL.

ATTACHMENT FOR GRINDING SCREW THREADED ARTICLES.

APPLICATION FILED JUNE 23,1911.

1,355,710c Patented Oct. 12, 1920.

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UNITED STATES PATENT OFFICE.

JOSEPH M. STRYHAL, OF WASHINGTON, DISTRICT OF COLUMBIA, ASSIGNOR 0F HALF TO WILLIAM M. MANIQN, 0F PHILADELPHIA, PENNSYLVANIA.

Specification of Letters Patent.

Patented Oct. 12, 1920.

Application filed June as, 1917. Serial No. 176,610.

To all whom it may concern:

Be it known that I, JOSEPH M. STRYHAL',

a citizen of the United States, residing at Washington, in the District of Columbia, have invented a certain new and useful Attachment for Grinding Screw Threaded Articles, of which the following is a specification.

The present invention relates tq an attachment for grinding and truing screwthreaded articles and has more particular relation to an attachment for grinding and truing male and female thread-gages, taps, hobs, dies and other screw-threaded articles and worm gears after the same have been cut and hardened or tempered.

Considerable difficulty has been experienced in the past in the manufacture of screw-threaded articles due to the warping of the screw-threads which invariably occurs during the hardening or tempering process, it being understood of course that the screwthreads are cut-while the metal is relatively soft. Totrue the screw-threads after hardening, as now practised, by means of lapping with emery, is a slow, expensive and altogether unsatisfactory and doubtful or uncertain procedure. I

The principal object of the presentinvention is to overcome the above recited disadvantageous features and provide an attachment in the form of a grinding device commercially adapted for the rapid, efiicient, accurate, reliable and certain truing of male and female screw-threads afterhardening thereof so that the same conform to the original contour or shape. A further object of the resent invention is to provide a'simple, e cient and comparatively inexpensive attachment, portable in character, which may be readily used in conjunction with a lathe or the like and which is so shaped and proportioned that it may replace the conventional tool-post or tool holding member during a grinding and truing operation.

still further object of the present invention resides in the providing of an attachment of this character having a maximum range of adjustment in order'to grind and true in an accurate and commercially satisfactory manner objects of large as Well as small' diameter. invention is to provide an attachment of the character stated equipped with a disk of abrading substance, as carborundum, revolubine A still further object of the present ble at a high rate of speed for cooperatively engaging with screw-threads to true the same rapidly, accurately and in a thoroughly reliable manner.

Another object of this invention is to prov1de a grinding attachment for a lathe or the like including a universally adjustable grlnding shaft revoluble at a high rate of speed, which attachment includes meansfor preventing the transmission of the driving vibration to the grinding disk.

With these and other. objects in viewas will hereinafter fully appear, the invention consists of the improvements hereinafter described and finally claimed.

The nature, characteristic features and scope of the invention will be, more fully understood from the following description, taken in connectionwith the accompanying driawlilngs forming part hereof, and in W 10 tion in position upon the tool carriage ready for use. I

Fig. 2 is a detached view of the attach.

ment in section taken upon the line'2'2 of,-

Fig.3.

Fig. 3 is a view in section taken-uponitheline 3-3 of Fig. 2. p

Fig.4 is a View in section taken uponthe line 44 of Fig. 2.

Fig. 5 is a fragmentary view in section of the pulle connection taken upon the line 5-5 of ig. 6.

Fig. 6 is a top or plan view of Fig. 5.

Figs. 7 to 12 inclusive are detail, detached views of the pulley and disk-shaft connectin%parts, hereinafter specificallyreferred to.

15. 13 1s a top or plan view of the comgrinding' attachment and disk-shaper in, operative position but detached from a lathe. j

For the purpose of illustrating my invention, I have shown in" the accompanying drawin one form thereof which is atpresent pre erred by me, since the same has been found in practice to give satisfactory and reliable results, although it is to be underthe attachment of the invention to a lathe for grinding and truing a thread-gage. However, I wish it understood that the attachment of the invention is applicable for internal and external grinding of other obects of various kinds. Referring now to ig. 1, 1O designates a lathe of conventional type, 11 representing the head-stock and 12 the tail stock thereof. The work, which in the present instance is a thread-gage 13 is operatively positioned between the respective stocks. The tool-carriage 14 of the lathe is shown in Fig. 3., In using the present attachment the conventional toolpost is removed from the tool-carriage 14 and the base-plate 15 of the grinding and truing attachment bolted thereto as at 16, the base-plate being apertured as at 17 for the reception of the bolts. The base-plate has formed integral therewith a pair of spaced uprights 18 connected across their tops by a horizontally disposed strip 19. Adjustable vertically between these uprights 18 in a slidable manner is a block 20, the uprights being grooved and the block provided with tongues engaging said grooves, as clearly shown in Fig. 2, to prevent lateral movement of the block. To permit of such vertical movement an adjusting nut 21 is employed which is rotatable through the strip 19 and has screw-threaded engagement with the taped portion 22 of the block 20. To clamp the block in adjusted position bolts 23 are employed which pass horizontally through slots 24 in the uprights 18 and engage taped portions of the block 20. So mounted upon the front face of the block 20 as to be capable of being adjusted in an arc of a circle is a plate 25 the front of which is mortised as at 26. To secure the proper adjustment of plate 25 use is made of a stud having an annular bearing face 27 and a pair of threaded extensions 28 and 29 of reduced diameter. The part 27 is rotatablyseated in the block 20, the threaded extension 28 engaging a taped portion'of the plate 25 and the threaded extension 29 being en aged by a nut for clamping the plate in i ixed position against the block 20 after proper adjustment has been secured. Adjustable endwise through the mortised pgrtion of the plate 25 isa member 30 provided with tenons for cooperatively engaging the said mortised plate. The member 30 has removably fixed to an extension 31 thereof a laterally disposed supporting arm 32 which forms a -U-shaped opening to accommodate-a pulley 33 to be presently described. Rotatably positioned with respect to the supporting arm 32 is an adjusting screw 34, see Fig. 2, the threaded end of engages the taped portion 35 of plate 25 whereby endwise adjustment of member 30, including supporting arm 32, may be effected with respect to plate 25. The free or front portion of member 30 constitutes a bearing for the driving shaft of the grinding or truing Wheel 36. This bearing is split as at 37, bolts 38 being present to clamp the split parts together to sustain against rotation a bushin 39 in which the shaft 40 is rotatable. 6ne end of this bushing is provided with a shoulder which abuts against the member 30 and the other end is threaded to receive a nut 42. for clamping the bushing against endwise movement. The shaft 40 is provided at one end with a screwthreadedportion to detachably receive the internally threaded stem 43,- which in turn removably holds, b means of a screw 44 in engagement'w'it the screw-threads of the stem 43, the grinding or truing disk 36. In practice the disk is made of carborundum. The other end of the shaft 40 has formed integral therewith a disk 45 provided with a projected cross-piece 46 upon its face, see Fig. 12. This cross-piece is rovidedwith a tapered depression 47. aving inter locked relation with the disk 45 is an annular plate 48 which inturn has interlocked relation with one end of the pulley 33. .In this connection it may be stated that the plate 48 is apertured therethrough as at 49 and it is provided upon one face with a cross-piece 50 for engaging a groove 51 upon the end of pulley 33, see Figs. 7, 8 and 9 and is grooved as at 52 upon its other face for engaging the cross-piece 46 of disk 45, see Figs. 10 and 12. ulley '33, which is tubular, is fitted with a bushin 53which is rotatable upon the free end 0 a sleeve 54 the other end of the sleeve having [screwthreaded relation with supporting arm 32 upon extension 31 and is fixed with respect thereto. Penetrating the sleeve 54 and hav ing screw-threaded relation with the outer end thereof, see Fig. 5, is a screw55 provided with an elongated aperture at its end to receive the pin 56 of a fiber center-piece 57 having a tapered portion 58, see Fig. 11, the part 58 being fitted to aperture 47 of disk45. The pulley and shaft 40 havin interlocked relation in the manner describe the connecting parts maybe properly centered with respect to shaft 40. Since the sleeve 54 is carried by fixed su port 32 and the screw 55 passes through this sleeve to support oneend of center-piece57 and the other end of piece 57 centers in shaft 40, the interlocked connection rotates around centerpiece 57 whereby thereis maintained a common center for the connecting parts. Any

7 wear between the connecting parts may be taken up by adjusting screw 55', a lock nut being present for maintainin the screw 55 in adjusted position. By t e above described connection, the grinding or truing disk 36 is caused to operate in a steadier manner than if the pulley were fixed directly upon shaft 40. Vibration as may be referred to the pulley is not transmitted to the disk 36 but is absorbed by the interlocking connection. Oil holes are present for the various bearing surfaces and are desig nated 58. That end of late 25 adjacent the disk 36 is provided wit dowel-pins 59 and with an opening 60 provided with mutilated screw-threads 61.

It is thought that the operation and mode of using the above described attachments may be readily understood from the above description. without resorting to a further and detailed account thereof except to state that in practice the work is placed in operative position upon a rotatable work holder, for instance, a lathe and the attachment mounted upon the tool-carriage. As the tool carriage is fed along the work at a predetermined rate, the grinding-disk is rotated independently of the work and at a greater rate.

It will now be apparent that I have de vised a novel and useful construction which embodies the features of advantage enumerated as desirable in the statement of the invention. and the above description and while I have in the present instance shown and described the preferred embodiment thereof which has been found in practice to give satisfactory and reliable results, it is to be understood that the same is susceptible of modification in various particulars without departing from the spirit or scope of the invention or sacrificing any of its advantages.

What I claim is:

1. A grinding attachment for the tool carriage of a lathe or the like, comprising a support, means providing a detachable connection therefor for detachably connecting the same to the tool carriage, a block-carried by said support, means for giving said block a vertical settin adjustment, a plate angularly adjustable a out a horizontal axis on said block, a member carried by said plate and formed with spaced bearings, a grinding shaft rotatably journaled in said bearings, a pulley mounted on said shaft intermediate said bearings and means for adjusting saidmember to produce an endwise adjustment of said shaft having a grinding shaft journaled for rotation therein carried by said plate, and manually operable means for giving said member a longitudinal setting adjustment.

2. A grinding attachment for the tool carriage of a lathe or the like, comprising a support, adapted for detachable connection therewith, a block vertically adjustable thereon, a plate angularly adjustable with respect to sald block, a member carried by and capable of endwise adjustment with respect to said plate, a rinding shaft journaled for rotation in said member, and provided with a grinding disk, a driving pulley mounted on said shaft, and means carried by said member for preventing the vibrations of said pulley from being transmitted to the grinding disk on said shaft.

3. A grinding attachment for the tool carriage of a lathe or the like comprising a support, means providing a detachable connection therefor to the tool carriage, a member mounted on said support, means for giving said member vertical, longitudinal and angular setting adjustments, a grinding shaft rotatabl journaled in said bearing member, a pul ey mounted on said shaft, and means for preventing the vibrations of said pulley from being transmitted to the grinding disk on said shaft.

4. A grinding attachment for the tool carriage of a lathe comprising a support, means for detachably connecting the same to the tool carriage, a member mounted on said support, means for giving said member vertical, horizontal and angular setting adjustments, a bearing on said member, a grinding shaft, rotatably journaled in said bearing, a supporting arm carried by said member and spaced from said bearing, a sleeve carried bylwsaid arm, a pulley rotatably journaled on said sleeve, a universal connection between said pulley and shaft, and adjustable means for maintaining the centers of said shaft and pulley in alinement.

5. A grinding attachment for the tool carriage of a lathe comprising a support, means for detachably connecting the same to the tool carriage, a member mounted on said support, means for giving said member vertical, horizontal and angular setting adjustments, a bearing on said member, a grinding shaft rotatably journaled in said bearing, a supporting arm carried by said member and spaced from said bearing, a sleeve carried by said arm, a pulley rotatably journaled on said sleeve between said arm and bearing, a universal connection between said pulley and shaft, and an adjusting screw passing through said sleeve, and a centering device carried by said screw engaging said shaft to maintain the centers of said shaft and pulley in alinement.

6. A grinding attachment for the tool carriage of a lathe comprising a support, means for detachably connecting the same to the tool-carriage, a member mounted on said support, means for giving said member vertical, horizontal and angular setting adjustments, a bearing on said member, a grinding shaft rotatably journaled in said bearing, a supporting arm carried by said member and spaced from said bearing, a

driving pulley rotatably-journaled between said bearing and arm and supported by the latter, and a universal driving connection between said pulley and said grmding shaft.

7. A grinding attachment for the tool carriage of a lathe or the like, comprising a support, means providing a detachable connection therefor to the tool carriage, a member mountedin said support, means for giving said-member vertical, and angular setting adjustments, a grinding shaft rotatably journaled in said bearing, and means for shifting said member to produce an adjustment endwise of said rinding shaft.

8. An attachment 0- the character stated embracing a support, a block vertically adjustable With respect thereto, a plate carried by and capable of adjustment in an arc of a circle with respect to said block, a member carried by and capable of endwise adjustment with respect to said plate, a shaft rotatable in said member, a pulley for one end of said shaft, means for interlocking the pulley with respect to said shaft and endwise movable means for adjusting said interlocking relation.

9. A grinding attachment of the character stated embracing an adjustable member, a grinding shaft rotatable therein, a pulley, means for interlocking the ulley and shaft together, a fiber centeringevice for maintaining said pulley and shaft centers in alinement and means for adjusting said centerin device endwise to take up wear of the inter ocking parts.

In testimony whereof I have hereunto signed my name.

JOSEPH M. STRYHAL. 

